6 Moreover, Rifaximin has been shown in previous studies to be effective at reducing HE parameters in cirrhotics.7-14 However, most reports on this subject have emanated from Europe. It has also been reported that combinatorial rifaximin and lactulose is superior to combined neomycin and lactulose for HE treatment.8 In addition, a recent randomized, selleck bio controlled study conducted in Spain found that rifaximin and lactitol, a nonabsorbable disaccharide, have similar efficacies for the treatment of acute HE.14 The present study is the first, prospective randomized study to compare the efficacy of rifaximin with that of lactulose for the short-term treatment of HE in Asia. No data is available upon whether ethnic background affects the effectiveness of rifaximin for the treatment of HE.

Our study confirms that rifaximin is as effective as lactulose for the treatment of HE in Korean patients. Administration at 1200 mg per day led to an objective and significant improvement in mental state, blood ammonia levels, and HE index. Moreover, no significant difference was found between rifaximin and lactulose in terms of their efficacies. These results suggest that ethnic differences do not significantly affect the efficacy of rifaximin as a HE treatment. In this study, the fact that hepatitis B virus is the predominant (75.9%) cause of HE should be considered. In Western countries, alcoholic abuse remains the most common etiology of liver cirrhosis with HE.18,19 Considering intestinal bacterial overgrowth due to alcohol,20 rifaximin might theoretically be a better choice in alcoholic HE than in viral hepatitisrelated HE.

However, our results are similar to those of Western studies concerning the efficacy of rifaximin for the treatment of HE, which suggests that the cause of HE is of secondary importance when considering rifaximin as a therapeutic regimen for HE. When we analyzed the clinical parameters of patients who showed an improvement with those who did not after rifaximin treatment, several factors were found to be significant by univariate analysis. However, limited patient numbers prevented multivariate analysis. We believe that further study of a larger number of patients would be necessary to identify those factors that determine responsiveness to rifaximin in HE treatment.

Interestingly, mean baseline ammonia level and HE index were higher in the improvement group than in the no-improvement group after rifaximin treatment, which suggests that rifaximin can be a first-line choice for the treatment of moderate to severe grade HE. The identification and correction of factors precipitating HE is of primary concern during the management of HE,29 because the correction of such factors usually results in improvement. Thus patients’ precipitating factors should GSK-3 be carefully considered in any future trial.